Oral solid gentamicin preparation using emulsifier and adsorbent.

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Oral gentamicin (GM) therapy faces challenges due to poor oral absorption.
• Developing effective oral solid dosage forms for poorly absorbable drugs like GM is crucial for improved patient compliance and therapeutic outcomes.

Purpose of the Study:

• To develop and evaluate an oral solid delivery system for gentamicin using various adsorbents.
• To assess the in vitro drug release and in vivo pharmacokinetic profiles of gentamicin formulated with different adsorbents.

Main Methods:

• Gentamicin was formulated with a surfactant (Labrasol) and solidified using adsorbents: microporous calcium silicate (Florite RE), magnesium alminometa silicate (Neusilin US2), and silicon dioxide (Sylysia 320).
• In vitro release studies and in vivo absorption studies in rats and dogs were conducted.
• Bioavailability was determined by comparing AUC values after oral and intravenous administration.

Main Results:

• All formulations showed high in vitro drug release (>94%) within 2 hours.
• The Florite RE 10 mg preparation exhibited the highest Cmax (2.14 µg/ml) and AUC (4.74 µg·h/ml) in rats, resulting in a bioavailability of 14.1%.
• Oral administration in dogs using an enteric capsule also yielded significant plasma GM levels (Cmax 1.26 µg/ml, AUC 2.59 µg·h/ml).

Conclusions:

• Adsorbent-based systems, particularly using microporous calcium silicate (Florite RE), are effective for developing oral solid dosage forms of poorly absorbable drugs like gentamicin.
• This approach offers a promising strategy for enhancing the oral delivery and therapeutic potential of challenging drug compounds.